Jamieson, Fausset and Brown on 2 Samuel 8:13

13. David gat him a name when he returned from smiting of the Syrians--Instead of Syrians, the Septuagint version reads "Edomites," which is the true reading, as is evident from 2Sa 8:14. This conquest, made by the army of David, was due to the skilful generalship and gallantry of Abishai and Joab. (1Ch 18:12; compare Psa 60:1, title.) The valley was the ravine of salt (the Ghor), adjoining the Salt Mountain, at the southwestern extremity of the Dead Sea, separating the ancient territories of Judah and Edom [Robinson].

2Sa 8:15-18. His Reign.